1. Field
Embodiments of the present invention relate to the electronics manufacturing industry and more particularly to in-situ cleaning and conditioning of plasma processing chambers.
2. Discussion of Related Art
As the feature size of microelectronic devices shrinks elemental contamination originating from the processing equipment employed to fabricate the devices becomes more detrimental to device performance. Plasma processing equipment, such as those designed to perform plasma etching, may include a variety of chamber materials, including alumina, yttria, and zirconia, and any of these can pose a source for metallic contamination of advanced devices. Such contamination can be all the more problematic as it may be a function of the chamber age.
Conditioning of a plasma processing chamber may be performed to prevent a plasma from interacting with the chamber materials and transferring contaminants from the chamber materials to the workpiece (e.g., wafer of devices under manufacture) during a plasma processing. For example, as shown in FIG. 1, a plasma etch chamber 100 includes a chuck 102 upon which a workpiece 101 is disposed during processing with a plasma 103. The chuck 102, chamber liner 105, chamber lid 107, and bottom surface 112 of gas nozzle 110 are all isolated from exposure to the plasma 103 by a chamber coating 115 which has been deposited onto the chamber materials with one or more plasma processes prior to loading the workpiece 101 in the plasma etch chamber 100.
However, a drawback of the chamber coating 115 is that the coating itself may cause contamination of the workpiece 101, often in the form of particulate defects when the coating sheds from the chamber materials and falls onto the underlying workpiece 101. As such, the practice of chamber coating may merely trade one type of device contamination for another.